We are attempting to determine the three-dimensional conformations and chemical groups relevant to biological interaction of cholinergic substances of several classes. We divide classes into agonists and antagonists of the ganglion, the autonomic post-ganglionic parasympathetic nervous junction, the motor-end plate and acetylcholinesterase. BIBLIOGRAPHIC REFERENCES: Peter Pauling. The Significance of Conformation in Psychotherapeutic Drugs, E. Usdin and I.S. Forrest, Marcell Dekker, New York, 1976. N. Datta and P. Pauling. J. Chem. Soc. (Lon) Perk II, 1977, in press.